Wisteria vines, for the most part, are not for the wimpy gardener. About 99.9% of the plants sold are Japanese wisteria (Wisteria floribunda) and Chinese wisteria (Wisteria sinensis)—thuggish Asian imports that frequently escape managed gardens. They climb the tallest trees, spread at light speed, and their muscular, twining stems can bend iron, crush an arbor, or throttle small trees to death. Still, we plant them for their pendant chains of beautiful, fragrant spring flowers. We’re so dumb.
Grumpy, are there any wisterias that are pretty and play nice? Why, yes, and they’re both native. Let me tell you about them.
Kentucky wisteria (Wisteria macrostachya) is found in the south-central United States. It’s more cold-hardy than the Asian types and suited to USDA Zones 3-9. It also blooms later than they do—in May or June, depending where you live—so the blooms are seldom zapped by a late frost. Fragrant, lavender-blue racemes up to 12 inches long cascade from its stems. The selection ‘Blue Moon’ (above) blooms up to three times a year once established, the spring bloom being the heaviest. It can grow 25 feet tall rather quickly, so don’t think you can just plant it and forget. A yearly pruning keeps it in check.
American wisteria (Wisteria frutescens) is another native worth a look. Think of it as a smaller, slower-growing version of Kentucky wisteria. It blooms at about the same time, but its flowers look quite different. Rather than chain-like, the 6-inch long racemes are bunched, looking like purple corncobs cut in half. They’re not quite as sweet-smelling as those of Kentucky wisteria. ‘Amethyst Falls,’ a popular selection, repeat blooms like ‘Blue Moon’ does, but it’s a less aggressive plant with thinner stems that won’t damage wooden arbors or trellises. It’s suited to USDA Zones 5-9 and needs little pruning.
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For best flowering, plant either vine in full sun and well-drained soil. Both set seed, so prune off the beanlike seed pods before they mature if you don’t want seedlings popping up.